Which of the following factors determines how harmful an introduced chemical will be on the environment?

Which statement describes john tuzo wilson’s contribution to the theory of plate tectonics? he proposed that plates carry parts of the seafloor. he theorized that pieces of earth move for a limited time. he suggested that the asthenosphere is broken into segments. he observed seafloor cracks similar to existing cracks in the continents.

Over half of the african-american population in the united states live in

Which of these is a drawback of using natural gas? a. it is fairly safe for use in homes.b. it burns more cleanly than crude oil products.c. scientists have developed new ways of extracting it.d. during its extraction, groundwater can be contaminated.